1. Field of the Invention
The invention relates to compound pistons for internal combustion engines.
2. Description of the Prior Art
Numerous types of compound pistons, i.e. pistons having a plurality of linked movable elements within each cylinder of the engine block, have been developed for internal combustion engines. In these prior art configurations, the top of the piston, i.e. the crown or head of the piston, is only partially extended at the upper end of the stroke. The maximum amount of compression, i.e. the maximum extension of the telescoping members, occurs when the crank is past dead center. The offset of some of these bell cranks, albeit slight, is enough to render the engine less efficient. Generally in the prior art, the two halves of the piston telescope as the piston moves up and then again as the piston reaches the bottom of the stroke. Among the prior art relative to expanding pistons having linkage systems which relatively move the pistons, as the connecting rod moves up and down, may be mentioned U.S. Pat. Nos. 1,379,115; 1,420,236; 1,430,491; 1,671,708; 2,368,412; 2,458,111; 3,034,362; 3,859,976 and 3,908,623.